Electric meter.



J. E. GRAYBILL & P. MQJUNKIN.

ELECTRIC METER. APPLIOATION FILED mm: a, 1904. 1,01 9,456. Patented Mar.5, 1912.

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J. E. GRAYBILL & P MoJUNKIN. ELECTRIC METER. APPLICATION IILED JUNE 9,1904.

1,01 9,456. Patented Mar. 5, 1912.

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UNITED STATES PATENT OFFICE.

JOHN E. GRAYBILL AND PAUL MGJUNKIN, OF YORK, PENNSYLVANIA, ASSIGNORS- TOGENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC METER.

Specification of Letters Patent.

Patented Mar. 5, 1912.

Application filed June 9, 1904. Serial No. 211,770;

To all wiwm it may concern Be it known that we, JOHN E. GRAYBILL andPAUL MOJUNKIN, citizens of the United States, and residents of York,county of York, and State of Pennsylvania, have in vented certain newand useful Improvements in Electric Meters, of which the following is aspecification.

This invention relates to meters for measuring electric energy which maybe used in connection with either alternating or direct currents.

The objectof the invention is to provide an improved meter as will behereinafter set forth.

In the accompanying drawings, Figure 1 is a front elevation of a meterembodying the invention, the door being shown as open so that a view ofthe interior is obtained; Fig. 2 is a diagrammatic illustration showingthe arrangement of circuits; and Fig. 3 shows a modification of themeans for transmit-ting the energy from the actuating to the indicatingmeans.

Referring to the drawings, the meter comprises an actuating means Awhich is alternately energized and deenergized, the energizing currentbeing proportional to that which is to be measured, an indicating deviceB which may consist of the usual dials over which hands are driven inthe usual manner by a train of gears, means whereby the actuating meansdrives the indicating device and a governing device C connected to theindicating device and actuating means and which opposes their movementin proportion to the speed at which it is driven.

The actuating means may comprise an electro-magnet 1 which may beconnected in series with the line carrying the current to be measured,but as it is sufficient if the magnet carries a current proportional tothe current to be measured, it is preferably connected in shunt to aresistance 2 located in the circuit in which it is desired to measurethe current flow. The actuating means may further comprise a lever 3pivoted to the frame or casing 5 at 6 and normally held in elevatedposition as by a spring 7 This lever may be of magnetizable material asiron, when it would in itself constitute an armature for theelectro-magnet, or it may be of non-magnetizable material, as brass, towhich a piece of iron 8 may be secured, which iron serves as an armatureto the magnet and causes the lever 3 to be oscillated as the magnet isenergized and denergized. Upon the lever 3 may be mounted a contact 9adapted to engage with a spring contact 10 and thereby complete thecircuit 11 of the electro-magnet when the lever is in its uppermostposition, but when the lever is attracted downwardly, it will, near thelower end of its movement, draw the contact 9 out of engagement with thespring 10 and thereby break the circuit of and denergize the magnet. Asshown the contact pin 9 is provided with two collars 9, 9 between whichthe lever 3 extends, the pin passing through a stationary guide 9. Theguide 9 is of such character that the contact pin will nor mally beheld'stationary in either of the positions to which it may be adjusted.With the contact positioned as shown in the drawing, the circuit 11 willremain closed until in its downward movement the lever 3 throughengagement with the collar 9 draws the contact away from spring 10, asabove referred to. It will be obvious that the energization anddeenergization of the electro-magnet may be accomplished in other waysthan by making and breaking its circuit as described. For instance, thedesired result may be secured by making and breaking a short circuitabout the electro-magnet, and other methods well known to personsskilled in the artmight be employed. Upon the deenergization of themagnet the spring 7 will return the lever 3 to its elevated position andnear the upper end of its travel will by engagement with the collar 9move the contact 9 into engagement with the spring 10 and remake thecircuit, when the electromagnet will again become energized and theoperation be repeated. Upon the end of the lever 3 may be mounted a pawl12, spring pressed into engagement with a ratchet wheel 13 looselymounted on a shaft 14 and connected thereto by an energy storing deviceas a spring 15. The shaft 14 is rotatably supported by the casing 5 andthe beveled gear 16 is fixed thereto. The beveled gear 16 engages with asimilar gearl? fixed to the vertical shaft 18 which is rotatablysupported by the casing. The shaft 18 is geared to the indicating devicein any suitable or known manner. Fixed to the shaft is a conductor 19forming part of the governing device, which may consist of a disk ofcopper or other conducting material.

The remainder of the device consists in a means for maintaining aconstant field within which the conductor or disk may be moved andpreferably consists in permanent magnets 20 fixed to the casing. Thefield within which the conductor moves being constant, it follows fromwell known laws that the opposition of the conductor or disk to motionis proportional to its speed, and therefore the opposition of thegoverning device to the movement of the actuating means and of theindicating device will vary in proportion to its speed. To preventbackward movement of the ratchet wheel 13 a pivoted dog 27 may be springpressed into engagement with the ratchet wheel.

For convenience in connecting the external circuits to the circuits ofthe meter, terminals 21 and 22 fixed to the casing are provided. Awindow 23 in the door 25 permits observation of the dials of theindicating device when the door is closed.

Having described an embodiment of the invention, its operation may beoutlined as follows: The parts being in the positions shown, if currentflows in the main circuit and therefore through the resistance 2,current will be shunted through the electromagnet 1 in proportion to thecurrent in the resistance 2. The magnet being thus energized it willattract the armature and thereby draw down the lever 3 against thespring 7. This movement of the lever opcrates through the pawl 12 toturn the ratchet wheel 13 and thereby wind up the spring 15. The tensionthus caused in the spring operates to turn the gears of the indicatingdevice and also the conductor 19 of the governing device. As the levernears the end of its travel under the efiect of the attraction exertedupon it by the electromagnet the contact 9 will be moved away from thespring 10, thereby breaking the circuit 11 and denergizing theelectromagnet. The lever then returns to its uppermost position underthe pressure of spring 7 Near the end of this return movement thecontact 9 will again make the circuit of the electro-magnet, when thelever will again be drawn toward the magnet and the ratchet wheel 13 canmove forward. At

' each impulse given the ratchet wheel greater tension will be producedin the spring 15, which in turn will tend to drive the conductor 19faster and faster, and, as we have seen, the opposition of thisconductor to rotation is proportional to its speed. Oscillation of thelever 3, as described, will continue until the tension in the spring 15becomes so great that the magnet can no longer attract its armatureagainst the force of the spring, which will occur when the speed of theconductor 19 has become such as to oppose motion by a force equal to theeffort exerted by the magnet upon the lever 3. This condition havingbeen reached, the arm will remain at rest until either the spring 15unwinds or the current in the magnet changes. If it be assumed that thecurrent remain constant, as the spring unwinds it will exert less forceupon the con ductor 19, which will have a tendency to slow down, but asthe decreased tension in the spring is now overcome by the efiort of theelctromagnet, a fresh impulse is given to the ratchet wheel and thespring is again wound to the proper tension. Should the current fall invalue the spring will have to become unwound to a greater extent andconsequently the conductor 19 be run at a slower speed before the lever3 can be actuated to drive the ratchet wheel and wind the spring.Conversely, should the current increase, the lever 3 will be operatedagainst a greater tension of the spring 15 which will therefore operatethe conductor 19 at a greater speed. It will thus be seen that the speedof the conductor 19 is proportional to the current in the resistance 2,and therefore the indicating device will be driven in proportion to thecurrent and the indications be recorded in any suitable manner.

If desired the energy storing device, as spring 15, may be dispensedwith and the motion of the ratchet wheel 13 be communicated directly tothe indicating device and conductor 19. It is preferable, however, thatthe force exerted by the pawl 12 shall be uniform throughout thisstroke. These objects may be accomplished by means of the modificationshown in Fig. 3, in which the pawl 12 is pivotally mounted upon a lever26 which comes into engagement with the end of the lever 3, the engagingends of the levers 3 and 26 being curved surfaces so that the leveragesaresuch that throughout the stroke of the lever B the pawl 12 exerts auniform effort upon the ratchet wheel 13. Other means for transmittingthe energy of the magnet uniformly to the driven mechanism than thatdescribed may be employed.

After starting the disk 19 acts as a fly wheel and maintains continuousoperation of the indicating device. Although shown as embodied in thegovernor, the fly wheel or other momentum device may be separatetherefrom.

While the invention has been illustrated in connection with a meter formeasuring current, it will be obvious to those skilled in the art thatit may be employed in a large number of meters for measuring electricenergy.

The principal difierence between volt meters and current measuringinstruments or ammeters is that the former are usually of much higherresistance than the latter,

r for the reason that the coils are usually connected across terminalsdilfering greatly in potential. In fact the current measuring instrumentillustrated may be considered as a volt meter which measures thepotential difference between the terminals of the resistance 2, whichpotential varies with the current flowing in said resistance.

This meter may be used for measuring current or voltage, as explainedabove. The meter may also be used as a watt meter if the iron armaturebe replaced by a coil and this coil energized by a current varyingeither with the current or potential in the circuit to be measured, theelectro-magnet being energized by a current varying with either thepotential or current in circuit. In this case it will be obvious thatthe pull upon the lever 3 will be proportional to the product of thefluxes set up by the two coils, that is, to the product of voltage andcurrent or the watts in the circuit to be measured, and thisconstruction being a well known one has not been illustrated.

WVhile the attraction of the armature by the electro-magnet has beenspoken of, it will be understood that repulsion of the armature isequivalent thereto and by an armature it is intended to express a memberwhich is set in motion by the magnetic effect of the electro-magnet,whether said member consists in magnetizable material or a coil of wirein which current may be caused to flow. The conductor 19 may be a woundarmature and numerous other modifications may be made without departingfrom the spirit and scope of the invention and it should not thereforebe limited to the specific construction illustrated.

Without being limited to the precise construction shown and described,what we claim is i 1. In an electric meter, in combination, analternately energized and denergized actuating electro-magnet,indicating means acted upon by each operation of said actuating magnet,a progressively moving governing means opposing the operation of saidactuating means in proportion to its speed and an energy storing deviceoperated by said electro-magnet and progressively driving said governingdevice.

2. In an electric meter, in combination, an alternately energized anddenergized actuating electro-magnet, an electro-magnet governing devicehaving an opposition to movement which is proportional to its speed, anindicating device progressively driven by said actuating magnet and anenergy storing device operated by said electro-magnet and progressivelydriving said governing device.

3. In an electric meter in combination, an alternately energized anddeinergized actuating electro-magnet, a governing device having anopposition to movement which is proportional to its speed, connectionsincluding a spring connecting said governing device and said actuatingmagnet and an indicating device connected with said governing device.

4:. In an electric meter, the combination with alternately energized anddeenergized electro-magnetic actuating means consisting of anelectro-magnet, of an armature oscillated thereby, a contact carried bysaid armature and located in the circuit of said electro-magnet, agoverning device comprising a conductor moving in a constant field, apawl and ratchet connection between said armature and said governingdevice, and an indicating device connected with said governing device,substantially as described.

5. In an electric meter, the combination with alternately energized anddeenergized electro-magnetic actuating means, of a governing devicehaving an opposition to movement which is proportional to its speed, anenergy storing device connecting said governing device and saidactuating means, and an indicating device connected with said governingdevice, substantially as described.

6. In an electric meter, the combination with alternately energized anddeenergized electro-magnetic actuating means consisting of an electromagnet, of an armature oscillated thereby, a contact carried by saidarmature and located in the circuit of said electro-magnet, a governingdevice comprising a conductor moving in a constant field, a pawl andratchet and a spring connecting said armature and said governing device,and an indicating device connected with said governing device,substantially as described.

7. In an electric meter, the combination with alternately energized anddeenergized electro-magnetic means consisting of an electro-magnet, ofan armature oscillated thereby, a contact carried by said armature andlocated in the circuit of said electro-magnet, a governing devicecomprising a conductor moving in a constant field, a pawl and ratchetand an energy storing device connecting said armature and said governingdevice, and an indicating device connected with said governing device,substantially as described.

8. In an electric meter, the combination with an electro-magneticactuating means having a stationary member and an oscillating member, ofa governing device comprising a conductor moving in a constant field, aratchet wheel, a spring connected with said conductor and said ratchetwheel, a pawl connected to said oscillating member of the actuatingmeans and engaging said ratchet wheel to move it in one direction only,and

an indicating device connected with said erning device, gearingconnecting the governing device and ratchet and including a coiledspring, means operated by the armature of the magnet for actuating theratchet and Winding said spring, an indicating device connected with thegoverning device, and contacts operated by said armature to energize anddeenergize the magnet, substantially as described.

10. In an electric meter, the combination with an electro-lnagnet, of anoscillating armature for the magnet, contacts operated by the armatureto energize and denergize the magnet as the armature is oscillated, aratchet adapted to be rotated as the armature is oscillated, a governingdevice, connections between the governing device and ratchet including aspring adapted to be placed under tension as the ratchet is turned bythe armature, and an indicating device 20 connected with the governingdevice, sub stantially as described.

In testimony whereof We have signed our names to this specification inthe presence of two subscribing Witnesses.

JOHN E. GRAYBILL. PAUL MOJUNKIN. lVitnesses:

ELLEN M. WVELLENSIEK, SMYsnR WVILLIAMS.

Gopies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

